1. Technical Field
This application relates to a device for supplying coolant into a shank of a rotary tool as well as a rotary tool, in particular a drill.
2. Background Information
In many existing rotary tools, for example milling cutters, reamers and drills, usually a coolant supply for lubricating and cooling the tool cutting edges is provided. In case of a central coolant supply, the coolant is supplied to the tool through a central coolant channel provided in a chuck in which the tool is clamped. In the chuck, the adjusting element is arranged, which includes the central coolant channel and which is usually arranged in such a way that it is adjustable in axial direction, to enable an adaptation to different tools. The coolant is supplied to cooling-lubricant channels extending in the tool.
More recent developments use minimum-quantity lubrication (MMS) or the so-called absolute-minimum lubrication. In these cases, an aerosol, i.e. a mixture of gas and liquid, is supplied as a coolant to the cutting edges of the tool. For such a minimum-quantity lubrication, a continuous and very uniform coolant supply is of decisive importance to prevent a running dry of the cutting edges. To promote this, high requirements are imposed on the coolant supply.
According to one example of an existing tool, the end of the adjusting element is provided with a truncated or conical adaptor. Complementary thereto, the end of the drill shank is also provided with a conical or truncated fitting or sealing face. At the end of the drill shank, a transverse channel is provided, which is situated opposite an outlet opening of the central coolant channel of the adjusting element. On each end of the transverse channel, an outlet opening of a cooling-lubricant channel passing through the drill is provided, said outlet openings lying in the area of the conical fitting face. The production of the conical design of the shank end with the transverse channel requires a relatively high expenditure.
According to another example of an existing tool, a separate insertion part is provided for an expansion chuck for distributing the coolant from a central coolant channel to the eccentrically arranged cooling-lubricant channels, the shank-side end of the drill abutting on said insertion part with surface contact.